How green are electric cars?

There's a huge amount of fuss in the press about a revolution in electric vehicles driven by the government. The 'greenness' of an electric car depends on where the electricity comes from - don't buy the 0gC02/km figures that are bandied about - that is patent nonsense. It is quite difficult to get precise data, but here's a rule of thumb from www.whatgreencar.com:

• Battery-electric cars using renewable energy provide the largest reduction in GHGs of almost 100%. 
  
• If 'standard-mix' electricity is used, battery electrics reduce greenhouse gases by around 40%. 
  
• Commercially produced pure bioethanol and biodiesel also provide significant reductions in greenhouse gases in the range 35%-90%, the reduction depending on feedstock crop used. 
  
• Due to their high fuel-efficiency, most petrol hybrids offer a reduction in greenhouse gases of around 25%. 
  
• Bi-fuel LPG and natural gas cars also produce modest reductions of around 15% due to better combustion and to their lower carbon content.

Tesla - the makers of the £90k electric sports car go further and say their car does 46gCO2/km, compared to an European average of 158gCO2/km, but that figure assumes the electricity comes from a brand new gas fired power station.

So electric is good, but not quite as good as some may claim!

What if the lights go out?

I was just stepping into the shower this morning when the water went cold. The lights had gone off too. I dried off the cold splash of water that had hit me before I could jump out and went and checked the fuse box. Everything was OK there, so we had a power cut.

I got dressed and went up to the newsagents - he was using two battery powered camping lights and a calculator to run the shop, and was worried about his perishable foodstuffs. The pedestrian crossing was out of order too. A symphony of burglar alarms rang out across the neighbourhood.

When I got back we lit the stove with a match to boil the kettle and had cereal rather than toast. My partner and I fought a battle over who was blocking whose light from the window in order to read the paper. It was eerily quiet with no fish tank pump or fridge humming in the background.

After breakfast I found I had about an hour of battery left on my laptop, but no broadband, so I checked my e-mail on my mobile phone. My work choice boiled down to what didn't require much access to the net as the clock was ticking on my battery reserves on both.

Ninety minutes after the cut started it ended, then we had half an hour of power followed by a further ten minute cut. Since then it has been fine and I'm still sighing big sighs of relief.

Now hundreds of millions of people across the world have no access to electricity at all, and many more suffer regular power cuts. 90 minutes without power is nothing on the grand scale of things, but everything changed or came to a halt while it lasted. Our luxuries, basic needs (food, warmth), communication systems, security systems and traffic control systems have all become incredibly dependent on a stable supply of electricity.

So what happens if the lights do go out? Will we descend into Mad Max-style post-apocalyptic anarchy or rebuild small self-sufficient communities and live in eco-harmony singing around the campfire? And do we want to go there?